On Joo Wan has taken a role in the upcoming drama "Masked Investigator," which stars Joo Sang Wook and Kim Sun Ah.

On, who last played prosecutor Lee Ho Sung in the drama "Punch" will be play a prosecutor once more in "Masked Investigator." The drama focuses on the detectives who investigate criminals and the prosecutors assigned to confirm their guilt. But "Masked Investigator" will have another kind of character. It will feature a masked investigator, a comic-book super hero type who pursues the crooks that somehow avoid paying for their crimes.

To achieve justice, this masked investigator occasionally has to break some rules. And he may find himself in trouble with the law.

Joo Sang Wook plays Ha Dae Cheol. He is a prosecutor by day, but he's often frustrated by the difficulty of catching and convicting the bad guys. As a result he takes matters into his own hands. He puts on a mask and pursues the bad guys.

Kim Sun Ah plays Yoo Min Hee, the chief of the violent crimes unit. She catches the crooks that Joo Won gets to prosecute but somehow some of them get away. As a police officer, she does not approve of anyone taking the law into his own hands.

So, where does On Joo Wan fit into this? He's playing Kang Hyun Woong, a prosecutor that cares more for the status quo and keeping the powerful in place than he does about the actual pursuit of justice. That will put him at odds with the character played by Joo Sang Wook. And if he is just a little crooked, overlooking crime to cater to the rich and powerful, he will also be at odds with Kim Sun Ah's character.

On Joo Wan has been busy for the last few years. He played Bojang of Goguryeo in "The Blade and the Petal" and Lee Hyun Myung in "The Idle Mermaid" before appearing in "Punch." He has also been seen in a few films lately, including "Obsessed" with Song Seung Hoon. This year he can be seen in the film "Time Renegade" with Lee Jin Wook and Lim Soo Jung.

Choi Jin Won will write the screenplay for "Masked Investigator." Kwak Jae Young is the director. The drama is expected to debut in May.